A Detailed Analysis of the Milky Way Warp Based on Classical Cepheids
Classical Cepheids (CCs) are important probes for the large-scale warp structure of the Milky Way. Using Gaia Data Release 3 CCs, we establish an optimal time-dependent warp model, where the warp height increases with radius following a power law, the line of nodes (LONs) exhibit linear twisting wit...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/adee1b |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849329561827803136 |
|---|---|
| author | Xiaoyue Zhou Xiaodian Chen Licai Deng Shu Wang Jiyu Wang Jianxing Zhang |
| author_facet | Xiaoyue Zhou Xiaodian Chen Licai Deng Shu Wang Jiyu Wang Jianxing Zhang |
| author_sort | Xiaoyue Zhou |
| collection | DOAJ |
| description | Classical Cepheids (CCs) are important probes for the large-scale warp structure of the Milky Way. Using Gaia Data Release 3 CCs, we establish an optimal time-dependent warp model, where the warp height increases with radius following a power law, the line of nodes (LONs) exhibit linear twisting with radius, following a leading spiral pattern, and the LONs undergo prograde evolution over time. Structurally, we identify significant warp features in the 5–9 kpc region of the Galactic disk, where the warp model performs better than the flat model. Beyond 15 kpc, the model with the second Fourier term does not fit the observations well, whereas the model with twisted LONs better matches the data. Kinematically, we derive expressions for the vertical velocities using direct differentiation and then calculate the precession rates for each CC. Our results intuitively indicate a nearly uniform and low warp precession rate of ω = 4.86 ± (0.88) _stat ± (2.14) _sys km s ^−1 kpc ^−1 beyond 12.5 kpc, in agreement with classical kinematic estimates. Based on these findings, we propose a simple yet comprehensive time-dependent warp model, ${Z}_{w}(t)=0.00019{R}^{3.08}\sin (\phi -(3.87R-41.79+4.86t))$ , which provides a unified framework for describing both the geometric and kinematic evolution of the Galactic warp. We analyze the impact of the adopted solar vertical velocity on the inferred warp precession rate and confirm the reliability of the measured precession rate. In addition, we find that the extinction treatment affects the warp amplitude in the inner disk, while its influence on the outer-disk warp structure and the precession rate is negligible. |
| format | Article |
| id | doaj-art-b2219f4091d34e73b6dc74740dbaa90a |
| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-b2219f4091d34e73b6dc74740dbaa90a2025-08-20T03:47:13ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01989221310.3847/1538-4357/adee1bA Detailed Analysis of the Milky Way Warp Based on Classical CepheidsXiaoyue Zhou0Xiaodian Chen1https://orcid.org/0000-0001-7084-0484Licai Deng2https://orcid.org/0000-0001-9073-9914Shu Wang3https://orcid.org/0000-0003-4489-9794Jiyu Wang4https://orcid.org/0009-0002-1155-284XJianxing Zhang5CAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; chenxiaodian@nao.cas.cn; School of Astronomy and Space Science, University of the Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; chenxiaodian@nao.cas.cn; School of Astronomy and Space Science, University of the Chinese Academy of Sciences , Beijing 100049, People’s Republic of China; Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University , Beijing 102206, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; chenxiaodian@nao.cas.cn; School of Astronomy and Space Science, University of the Chinese Academy of Sciences , Beijing 100049, People’s Republic of China; Department of Astronomy, China West Normal University , Nanchong 637009, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; chenxiaodian@nao.cas.cn; Department of Astronomy, China West Normal University , Nanchong 637009, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; chenxiaodian@nao.cas.cn; School of Astronomy and Space Science, University of the Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; chenxiaodian@nao.cas.cn; School of Astronomy and Space Science, University of the Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaClassical Cepheids (CCs) are important probes for the large-scale warp structure of the Milky Way. Using Gaia Data Release 3 CCs, we establish an optimal time-dependent warp model, where the warp height increases with radius following a power law, the line of nodes (LONs) exhibit linear twisting with radius, following a leading spiral pattern, and the LONs undergo prograde evolution over time. Structurally, we identify significant warp features in the 5–9 kpc region of the Galactic disk, where the warp model performs better than the flat model. Beyond 15 kpc, the model with the second Fourier term does not fit the observations well, whereas the model with twisted LONs better matches the data. Kinematically, we derive expressions for the vertical velocities using direct differentiation and then calculate the precession rates for each CC. Our results intuitively indicate a nearly uniform and low warp precession rate of ω = 4.86 ± (0.88) _stat ± (2.14) _sys km s ^−1 kpc ^−1 beyond 12.5 kpc, in agreement with classical kinematic estimates. Based on these findings, we propose a simple yet comprehensive time-dependent warp model, ${Z}_{w}(t)=0.00019{R}^{3.08}\sin (\phi -(3.87R-41.79+4.86t))$ , which provides a unified framework for describing both the geometric and kinematic evolution of the Galactic warp. We analyze the impact of the adopted solar vertical velocity on the inferred warp precession rate and confirm the reliability of the measured precession rate. In addition, we find that the extinction treatment affects the warp amplitude in the inner disk, while its influence on the outer-disk warp structure and the precession rate is negligible.https://doi.org/10.3847/1538-4357/adee1bCepheid variable starsMilky Way diskGalaxy structureStellar kinematics |
| spellingShingle | Xiaoyue Zhou Xiaodian Chen Licai Deng Shu Wang Jiyu Wang Jianxing Zhang A Detailed Analysis of the Milky Way Warp Based on Classical Cepheids The Astrophysical Journal Cepheid variable stars Milky Way disk Galaxy structure Stellar kinematics |
| title | A Detailed Analysis of the Milky Way Warp Based on Classical Cepheids |
| title_full | A Detailed Analysis of the Milky Way Warp Based on Classical Cepheids |
| title_fullStr | A Detailed Analysis of the Milky Way Warp Based on Classical Cepheids |
| title_full_unstemmed | A Detailed Analysis of the Milky Way Warp Based on Classical Cepheids |
| title_short | A Detailed Analysis of the Milky Way Warp Based on Classical Cepheids |
| title_sort | detailed analysis of the milky way warp based on classical cepheids |
| topic | Cepheid variable stars Milky Way disk Galaxy structure Stellar kinematics |
| url | https://doi.org/10.3847/1538-4357/adee1b |
| work_keys_str_mv | AT xiaoyuezhou adetailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT xiaodianchen adetailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT licaideng adetailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT shuwang adetailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT jiyuwang adetailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT jianxingzhang adetailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT xiaoyuezhou detailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT xiaodianchen detailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT licaideng detailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT shuwang detailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT jiyuwang detailedanalysisofthemilkywaywarpbasedonclassicalcepheids AT jianxingzhang detailedanalysisofthemilkywaywarpbasedonclassicalcepheids |